Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar /ˈpɒp.lər/, aspen, and cottonwood.

In the September 2006 issue of Science Magazine, the Joint Genome Institute announced that the Western Balsam Poplar (P. trichocarpa) was the first tree whose full DNA code had been determined by DNA sequencing.

Description

The genus has a large genetic diversity, and can grow from anywhere between 15–50 m (49–164 ft) tall, with trunks of up to 2.5 m (8 ft 2 in) diameter.

The bark on young trees is smooth, white to greenish or dark grey, often with conspicuous lenticels; on old trees it remains smooth in some species, but becomes rough and deeply fissured in others. The shoots are stout, with (unlike in the related willows) the terminal bud present. The leaves are spirally arranged, and vary in shape from triangular to circular or (rarely) lobed, and with a long petiole; in species in the sections Populus and Aigeiros, the petioles are laterally flattened, so that breezes easily cause the leaves to wobble back and forth, giving the whole tree a "twinkling" appearance in a breeze. Leaf size is very variable even on a single tree, typically with small leaves on side shoots, and very large leaves on strong-growing lead shoots. The leaves often turn bright gold to yellow before they fall during autumn.

Populus is a genus of plants.

Populus, populace, or populous may refer to:

See also

The 16 geomantic figures are the primary symbols used in divinatory geomancy. Each geomantic figure represents a certain state of the world or the mind, and can be interpreted in various ways based upon the query put forth and the method used to generate the figures. When geomancy was introduced to Europe in the Middle Ages, the figures acquired astrological meanings and new forms of interpretation. The figures bear superficial resemblance to the ba gua, the eight trigrams used in the I Ching, a Chinese classic text.

Properties of the figures

Each of the figures is composed of four lines, each line containing either one or two points. Each line represents one of the four classical elements: from top to bottom, the lines represent fire, air, water, and earth. When a line has a single point, the element is said to be active; otherwise, with two points, the element is passive. Because there are four lines, and since each line can be either active or passive, there are 2⁴, or 16, different figures. The different combinations of elements yields different representations or manifestations of the figure's energy.